Definition of photosystem in English:



  • A biochemical mechanism in plants by which chlorophyll absorbs light energy for photosynthesis. There are two such mechanisms (photosystems I and II) involving different chlorophyll-protein complexes.

    ‘In photosystem II, a different chlorophyll-protein complex absorbs light at the wavelength of 680 nm.’
    • ‘Both types of photosystems differ in size, pigment and protein composition, and charge.’
    • ‘In higher plant chloroplasts, many pigment-binding proteins are inserted into the thylakoid membrane and organized into multisubunit complexes called photosystems.’
    • ‘These trapping kinetics are much slower than observed in photosystem I, the other photosystem of oxygenic photosynthesis.’
    • ‘Thus state transitions appear to act as a mechanism to balance excitation of the two photosystems under changing light regimes.’



/ˈfōdōˌsistəm/ /ˈfoʊdoʊˌsɪstəm/